1. Technical Field
This invention relates to a process and apparatus for the recovery of lead shot, bullets and slugs primarily from old firing ranges, both military and commercial, as well as private shooting clubs and ranges. The lead material is recovered from old mounds of firing ranges and hillsides which serve as backstops for such ranges.
2. Background Information
Contamination of ground water by the concentrated lead deposits found in the backstops of firing ranges, including military, commercial and private, appears to be the next major item on the agenda of the U.S. Environmental Protection Agency for cleanup of the environment. A new strategic goal for the military industry is an environmental cleanup program aimed at restoring the environment and reducing pollution at thousands of military and other government military-industrial installations in the United States and abroad which have been contaminated with untold amounts of toxic substances. One of the greatest toxic substances is lead and lead alloys which have been residing in place, especially concentrated in firing ranges where lead shot, bullets and slugs have been in situ in considerable concentrations, and increasingly contaminating sources of ground water and adjacent aquifers. Very little prior art exits which is capable of providing processes and apparatus for treating such lead deposits by their collection and/or removal to prevent ground water contamination, and recovery for reuse of the lead.
Most of the known prior art relates to the recovery of lead from waste storage batteries such as disclosed in U.S. Pat. No. 3,393,876 to Elmore and U.S. Pat. No. 4,397,424 to Zappa et al. which relate to battery reclaiming methods and apparatus. Neither of the foregoing references is applicable to the recovery of lead shot, bullets and slugs from shooting range backstops wherein the lead concentration may vary very widely depending upon the previous use of the ranges, some of which date back for decades of military use and, in some cases, nearly a century.
This invention relates to the recovery of metallic lead, lead oxide and lead alloys from mounds and hillsides backing all kinds of shooting ranges from small arms fire as well as heavier arms fire where the lead projectiles have resided in both soil and rocky environments for extremely lengthy time periods. More particularly, this invention relates to the separation of the lead and lead-containing materials from the non-lead containing materials which normally consist of soil, sand, clay and rocky land which constitutes the firing range backstops. The former are commonly called the valued materials wherein the latter are non-valued materials.
The subject invention possesses increasingly greater value not only in the recovery of the lead, lead oxide and lead alloys for reuse but their elimination from soil deposits which are causing contamination of ground water in literally thousands of locations throughout the United States and abroad. The sites vary from Civil War battlefields to past and present military training bases as well as those used for competitive shooting matches such as Camp Perry in Ohio. The importance of eliminating such contaminants as lead from ground water is becoming increasingly important for protection of water sources and cleanup of sources which are increasingly being designated as contaminated by lead and other toxic substances. It is becoming increasingly important to the United States Government that both military and military-industrial installations be brought into compliance with the environmental laws. It is estimated that this military-industrial environmental project could take as long as 30 years to complete and cost 400 billion dollars, and both the Energy and Defense Departments of the U.S. Government are spending increased amounts of time and money on such projects.